Communication Service Providers are deploying a large number of Ethernet and IP services across networks and across a large number of Network Equipment Manufacturers (NEMs).
Network Elements (NEs) in today's networks are owned and managed by many parties that have interests in different portions of the Ethernet networks. To support the different needs of these parties, different types of services are being deployed over these networks.
The support for Ethernet performance monitoring, test and turn-up functions differs largely from one network equipment provider to another and this increases the operation complexity of deploying Ethernet based services across networks and across equipment vendors. The required capabilities are not always supported on all networking elements. And when supported, these capabilities may not be implemented consistently across different equipment vendors making it hard to manage with a single network management system.
Many networking elements (NEs) have pluggable transceiver ports. The pluggable transceivers inserted therein can be SFPs, XFPs, SFP+, CFPs, an so on. The basic functionality of a pluggable transceiver is to forward traffic between two interfaces in both directions. Traditional pluggable transceivers are very small (e.g. small form-factor) and perform very limited functionality but have the advantage of being part of most existing networking equipment by most network equipment manufacturers. Pluggable transceivers are pluggable in the sense that they are easily replaceable components that have a common and widely accepted physical interface on network equipment. Small form-factor pluggables (SFPs) are a popular industry format jointly developed and supported by many network equipment manufacturers and vendors. Enhanced small form-factor pluggable (SPF+) supports data rates up to 10 Gbit/s.
Pluggable transceivers provide input and output interfaces between network elements like switches, routers, etc. and fiber optic or electrical cables. Some of these interfaces perform conversions between optical and electrical signals. Small form-factor pluggable (SFP) transceivers support communications standards including synchronous optical networking (SONET), synchronous digital hierarchy (SDH), gigabit Ethernet and fiber channel. They also allow the transport of fast Ethernet and gigabit Ethernet LAN packets over time-division-multiplexing-based WANs, as well as the transmission of E1/T1 streams over packet-switched networks. Other interfaces are purely electrical, for example copper SFPs that do not contain an optical-electrical conversion or use fiber optic cables.
Pluggable transceivers typically follow a very detailed specification defined under industry MSAs (MultiSource Agreements). Pluggable transceivers are globally accepted by the networking community. Their small mechanical form factor and their simple interfaces are well defined. Furthermore, programmable gate arrays such as FPGAs have decreased in physical requirements sufficiently that they can be included within a pluggable transceiver without increasing their physical size and without substantially changing the throughput, power and heat dissipation requirements.
By adding programmable logic gate devices on these pluggable transceivers, they become programmable pluggable transceivers. By installing programmable pluggable transceivers in NEs, monitoring and networking functions can be added directly at the interfaces of these NEs, providing a cost effective and unified way to add these functionalities onto existing network elements as illustrated in FIG. 1.
FIG. 1 illustrates a series of Network Elements (NEs) 2, 4, 6 each having programmable pluggable transceivers 8 connected in a segment of a communication network 100. The NEs may be heterogeneous because some NEs may be provided by some manufacturers, and some by others. In FIG. 1, NEs 2, 4, 6 are connected in the network 100 such as by fiber optical or electrical cabling providing datapaths 16, 18, 20, 22. The NEs 2, 4, 6 have ports to receive pluggable transceivers 8 which provide interfaces between NEs 2, 4, 6 over the datapaths 16, 18, 20, 22 of the network 100. Any number of ports may exist on an NE 2, 4, 6 and not all ports require a transceiver or a programmable pluggable transceiver 8. The datapaths 16, 18, 20, 22 include service traffic datapaths, host 2-wire interface datapaths, and i2C bus datapaths (i2C is trade-mark of NXP Semiconductor). The datapaths may transmit frames including serial data streams.
The basic pass-through functionality of a transceiver 8 is to pass service traffic data through the transceiver in a transparent and hitless manner. This requires converting, if necessary, signals from the line-side where data is sent and received over fiber optic or electrical cabling to host-side where data is sent and received between the transceiver 8 and a network element 2, 4, 6 into which the transceiver 8 is plugged. Generally, transparent and hitless transmission implies transmission through the transceiver cannot be detected by other devices handling the service traffic data. The transceiver handles the data without dropping, corrupting or unintentionally changing it at the full line rate or minimum throughput rate of the network. One exception to the transparent and hitless functionality is that some transceivers are designed to make minor changes to the signal traffic data, such as changing the frame encapsulation without affecting the payload.
The pluggable transceivers 8 are programmable pluggable transceivers because they include a programmable logic gate array 10 within the transceiver. One such programmable pluggable transceiver 8′ is enlarged in FIG. 1 to show greater detail. Typically, the programmable logic gate array 10 is disposed between the line interface 12 and the host interface 14 such that the logic gate array 10 intersects both datapaths 16, 18 through the transceiver 8′. The logic gate array 10 may comprise any programmable logic gate array, for example FPGA, FPLA, PLA, CPLD, programmable ICs and so on.
The commonly known functionality of logic gate arrays such as FPGAs to be re-programmed and upgraded permits changing the functionality embedded in a programmable pluggable transceiver's logic gate array. Remote upgrade and partial reconfiguration capabilities are already available in certain logic device families, including FPGAs. Remote Upgrade allows the logic gate array to be upgraded in situ from a remote location. Partial Reconfiguration allows reconfiguring a portion of a logic gate array while other portions of the logic gate array remain operational and unchanged during the upgrade. Logic partitioning may be applied when performing partial reconfiguration of logic gate arrays to segregate the functionality that is being upgraded. Logic partitioning segments the contents of the logic gate array into distinct sections. A logic gate array may be partitioned based on contiguously addressed physical blocks of the array, or it may be partitioned non-contiguously and additional logic manages which blocks are associated with which partitions.
Because the logic gate array 10 is programmable, the programmable pluggable transceiver 8 may be programmed for any functionalities and has the potential to be upgraded for any number of reasons. For example: supporting new protocols, patch implementation to fix bugs, supporting a wide range of functionalities that cannot all concurrently reside in the logic gate array (for example, due to FPGA size restrictions), upgrading many transceivers to the same version across a network, customer and/or application specific functionalities, and so on.
Upgrading the logic gate array 10 may be achieved by removing the programmable pluggable transceiver from service and installing it into custom hardware for performing upgrades to the logic gate array 10. Upgrading may also be achieved while the programmable pluggable transceiver 8 is plugged into an NE 2, 4, 6 by disabling the transceiver and applying upgrades remotely. Unfortunately, both of these upgrade methods are service affecting. They are service affecting because the programmable pluggable transceiver 8 cannot perform its basic data forwarding and conversion functionality while such upgrade methods are applied to the functionality in the logic gate array. It would be advantageous to be able to upgrade a programmable pluggable transceiver while the transceiver is in service and without or with only minimally affecting the transceiver's through traffic.